Experimental investigation on regulated and unregulated emissions of a diesel/methanol compound combustion engine with and without diesel oxidation catalyst

The use of methanol in combination with diesel fuel is an effective measure to reduce particulate matter (PM) and nitrogen oxides (NOx) emissions from in-use diesel vehicles. In this study, a diesel/methanol compound combustion (DMCC) scheme was proposed and a 4-cylinder naturally-aspirated direct-injection diesel engine modified to operate on the proposed combustion scheme. The effect of DMCC and diesel oxidation catalyst (DOC) on the regulated emissions of total hydrocarbons (THC), carbon monoxide (CO), NOx and PM was investigated based on the Japanese 13 Mode test cycle. Certain unregulated emissions, including methane, ethyne, ethene, 1,3-butadiene, BTX (benzene, toluene, xylene), unburned methanol and formaldehyde were also evaluated based on the same test cycle. In addition, the soluble organic fraction (SOF) in the particulate and the particulate number concentration and size distribution were investigated at certain selected modes of operation. The results show that the DMCC scheme can effectively reduce NOx, particulate mass and number concentrations, ethyne, ethene and 1,3-butadiene emissions but significantly increase the emissions of THC, CO, NO₂, BTX, unburned methanol, formaldehyde, and the proportion of SOF in the particles. After the DOC, the emission of THC, CO, NO₂, as well as the unregulated gaseous emissions, can be significantly reduced when the exhaust gas temperature is sufficiently high while the particulate mass concentration is further reduced due to oxidation of the SOF.     

Emission reduction from diesel engine using fumigation methanol and diesel oxidation catalyst

This study is aimed to investigate the combined application of fumigation methanol and a diesel oxidation catalyst for reducing emissions of an in-use diesel engine. Experiments were performed on a 4-cylinder naturally-aspirated direct-injection diesel engine operating at a constant speed of 1800 rev/min for five engine loads.The experimental results show that at low engine loads, the brake thermal efficiency decreases with increase in fumigation methanol; but at high loads, it slightly increases with increase in fumigation methanol. The fumigation method results in a significant increase in hydrocarbon (HC), carbon monoxide (CO), and nitrogen dioxide (NO₂) emissions, but decrease in nitrogen oxides (NO_x), smoke opacity and the particulate mass concentration. For the submicron particles, the total number of particles decreases. In all cases, there is little change in geometrical mean diameter of the particles. After catalytic conversion, the HC, CO, NO₂, particulate mass and particulate number concentrations were significantly reduced at medium to high engine loads; while the geometrical mean diameter of the particles becomes larger. Thus, the combined use of fumigation methanol and diesel oxidation catalyst leads to a reduction of HC, CO, NO_x, particulate mass and particulate number concentrations at medium to high engine loads.     

Investigation on the gaseous and particulate emissions of a compression ignition engine fueled with diesel-dimethyl carbonate blends

The effect of dimethyl carbonate (DMC) on the gaseous and particulate emissions of a diesel engine was investigated using Euro V diesel fuel blended with different proportions of DMC. Combustion analysis shows that, with the blended fuel, the ignition delay and the heat release rate in the premixed combustion phase increase, while the total combustion duration and the fuel consumed in the diffusion combustion phase decrease. Compared with diesel fuel, with an increase of DMC in the blended fuel, the brake thermal efficiency is slightly improved but the brake specific fuel consumption increases. On the emission side, CO increases significantly at low engine load but decreases at high engine load while HC decreases slightly. NO_x reduces slightly but the reduction is not statistically significant, while NO₂ increases slightly. Particulate mass and number concentrations decrease upon using the blended fuel while the geometric mean diameter of the particles shifts towards smaller size. Overall speaking, diesel-DMC blends lead to significant improvement in particulate emissions while the impact on CO, HC and NO_x emissions is small.     

Experimental investigation on regulated and unregulated emissions of a diesel engine fueled with ultra-low sulfur diesel fuel blended with biodiesel from waste cooking oil

Experiments were conducted on a 4-cylinder direct-injection diesel engine using ultra-low sulfur diesel, bi oesel and their blends, to investigate the regulated and unregulated emissions of the engine under five engine loads at an engine speed of 1800 rev/min. Blended fuels containing 19.6%, 39.4%, 59.4% and 79.6% by volume of biodiesel, corresponding to 2%, 4%, 6% and 8% by mass of oxygen in the blended fuel, were used. Biodiesel used in this study was converted from waste cooking oil.The following results are obtained with an increase of biodiesel in the fuel. The brake specific fuel consumption and the brake thermal efficiency increase. The HC and CO emissions decrease while NO_x and NO₂ emissions increase. The smoke opacity and particulate mass concentrations reduce significantly at high engine load. In addition, for submicron particles, the geometry mean diameter of the particles becomes smaller while the total number concentration increases. For the unregulated gaseous emissions, generally, the emissions of formaldehyde, 1,3-butadiene, toluene, xylene decrease, however, acetaldehyde and benzene emissions increase.The results indicate that the combination of ultra-low sulfur diesel and biodiesel from waste cooking oil gives similar results to those in the literature using higher sulfur diesel fuels and biodiesel from other sources.     

Experimental study on particulate and NOx emissions of a diesel engine fueled with ultra low sulfur diesel, RME-diesel blends and PME-diesel blends

Ultra low sulfur diesel and two different kinds of biodiesel fuels blended with baseline diesel fuel in 5% and 20% v/v were tested in a Cummins 4BTA direct injection diesel engine, with a turbocharger and an intercooler. Experiments were conducted under five engine loads at two steady speeds (1500 rpm and 2500 rpm). The study aims at investigating the engine performance, NO_x emission, smoke opacity, PM composition, PM size distribution and comparing the impacts of low sulfur content of biodiesel with ULSD on the particulate emission. The results indicate that, compared to base diesel fuel, the increase of biodiesel in blends could cause certain increase in both brake specific fuel consumption and brake thermal efficiency. Compared with baseline diesel fuel, the biodiesel blends bring about more NO_x emissions. With the proportion of biodiesel increase in blends, the smoke opacity decreases, while total particle number concentration increases. Meanwhile the ULSD gives lower NO_x emissions, smoke opacity and total number concentration than those of baseline diesel fuel. In addition, the percentages of SOF and sulfate in particulates increase with biodiesel in blends, while the dry soot friction decreases obviously. Compared with baseline diesel fuel, the biodiesel blends increase the total nucleation number concentration, while ULSD reduces the total nucleation number concentration effectively, although they all have lower sulfur content. It means that, for ULSD, the lower sulfur content is the dominant factor for suppressing nucleation particles formation, while for biodiesel blends, lower volatile, lower aromatic content and higher oxygen content of biodiesel are key factors for improving the nucleation particles formation. The results demonstrate that the higher NO_x emission and total nucleation number concentration are considered as the big obstacles of the application of biodiesel in diesel engine.     

Experimental investigation of engine emissions with marine gas oil-oxygenate blends

This paper investigates the diesel engine performance and exhaust emissions with marine gas oil-alternative fuel additive. Marine gas oil (MGO) was selected as base fuel for the engine experiments. An oxygenate, diethylene glycol dimethyl ether (DGM), and a biodiesel (BD) jatropha oil methyl ester (JOME) with a volume of 10% were blended with the MGO fuel. JOME was derived from inedible jatropha oil. Lower emissions with diesel-BD blends (soybean methyl ester, rapeseed methyl ester etc.) have been established so far, but the effect of MGO-BD (JOME) blends on engine performance and emissions has been a growing interest as JOME (BD) is derived from inedible oil and MGO is frequently used in maritime transports. No phase separation between MGO-DGM and MGO-JOME blends was found. The neat MGO, MGO-DGM and MGO-JOME blends are termed as MGO, Ox10 and B10 respectively. The experiments were conducted with a six-cylinder, four-stroke, turbocharged, direct-injection Scania DC 1102 (DI) diesel engine. The experimental results showed significant reductions in fine particle number and mass emissions, PM and smoke emissions with Ox10 and B10 fuels compared to the MGO fuel. Other emissions including total unburned hydrocarbon (THC), carbon monoxide (CO) and engine noise were also reduced with the Ox10 and B10 fuels, while maintaining similar brake specific fuel consumption (BSFC) and thermal efficiency with MGO fuel. Oxides of nitrogen (NOx) emissions, on the other hand, were slightly higher with the Ox10 and B10 fuels at high engine load conditions.     

Performance and emission analysis of diesel engine with design modifications on piston crown

The present work aims to enhance the performance of the existing diesel engine by modifying the piston design. Swirl piston is used to induce turbulence as an active enhancement technique. The engine is run at 250 bar injection pressure and 17.5 compression ratio by varying the injection timings. A stirrer is introduced at the top of the piston so as to inculcate more turbulence to incoming charge that improves the fuel vaporisation rate. Whirling motion is created in the combustion chamber by rotating the blades on the cavity/bowl of the reciprocating piston head. A simple link mechanism is provided to convert the oscillatory motion of connecting rod into the rotary motion of the vane. The experimental result clears that the brake-specific fuel consumption is reduced by 8.7%, brake thermal efficiency is enhanced by 9.4%, 11.8% of CO emissions are controlled and NO _x emissions are controlled by 27% is observed with the modified piston compared to the normal piston at retarded injection timing.     

Enhancement in the performance of a diesel engine fuelled with Pongamia methyl ester and n-butanol as oxygenated additive

The present paper investigates the performance and emission characteristics of a single-cylinder, four-stroke diesel engine fuelled with Pongamia methyl ester (PME) and n-butanol, at different loading conditions. Two blends of n-butanol–PME (10% and 20% n-butanol with PME on a volumetric basis) were prepared. The experimental results showed a significant improvement in the brake thermal efficiency of the engine with the blends and were found to increase with increasing percentage of n-butanol in the blends. The blended fuels also show lower emission such as carbon monoxide (CO), oxides of nitrogen (NO_x) and smoke opacity. However, unburned hydrocarbon (HC) emission was found to be slightly increased. Thus, it is concluded that the biodiesel with 20% n-butanol blend showed better results with respect to efficiency and emissions point of view compared with biodiesel.     

Emissions characteristics of a diesel engine operating on biodiesel and biodiesel blended with ethanol and methanol

Euro V diesel fuel, pure biodiesel and biodiesel blended with 5%, 10% and 15% of ethanol or methanol were tested on a 4-cylinder naturally-aspirated direct-injection diesel engine. Experiments were conducted under five engine loads at a steady speed of 1800 r/min. The study aims to investigate the effects of the blended fuels on reducing NO_x and particulate. On the whole, compared with Euro V diesel fuel, the blended fuels could lead to reduction of both NO_x and PM of a diesel engine, with the biodiesel-methanol blends being more effective than the biodiesel-ethanol blends. The effectiveness of NO_x and particulate reductions is more effective with increase of alcohol in the blends. With high percentage of alcohol in the blends, the HC, CO emissions could increase and the brake thermal efficiency might be slightly reduced but the use of 5% blends could reduce the HC and CO emissions as well. With the diesel oxidation catalyst (DOC), the HC, CO and particulate emissions can be further reduced.     

Emission reduction potential of using gas-to-liquid and dimethyl ether fuels on a turbocharged diesel engine

A study of engine performance characteristics and both of regulated (CO, HC, NO_x, and smoke) and unregulated (ultrafine particle number, mass concentrations and size distribution) emissions for a turbocharged diesel engine fueled with conventional diesel, gas-to-liquid (GTL) and dimethyl ether (DME) fuels respectively at different engine loads and speeds have been carried out. The results indicated that fuel components significantly affected the engine performance and regulated/unregulated emissions. GTL exhibited almost the same power and torque output as diesel, while improved fuel economy. GTL significantly reduced regulated emissions with average reductions of 21.2% in CO, 15.7% in HC, 15.6% in NO_x and 22.1% in smoke in comparison to diesel, as well as average reductions in unregulated emissions of total ultrafine particle number (N_tot) and mass (M_tot) emissions by 85.3% and 43.9%. DME can significantly increase torque and power, compared with the original diesel engine, as well as significantly reduced regulated emissions of 40.1% in HC, 48.2% in NO_x and smoke free throughout all the engine conditions. However, N_tot for DME is close to that for diesel. The reason is that the accumulation mode particle number emissions for DME are very low due to the characteristics of oxygen content and no C-C bond, which promotes the processes of nucleation and condensation of the semi-volatile compounds in the exhaust gas, as a result, a lot of nucleation mode particles produce.     

Effect of TiO2 and nozzle geometry on diesel emissions fuelled with biodiesel blends

In this present study, the compression ignition engine was designed to run on CIME (Calophyllum inophyllum methyl ester) biodiesel with nanoparticles. The TiO₂ nanoparticle is added to the biodiesel in the form of nanofluid at concentration levels of 100?ppm whereas ethanox is added at levels of 100, 200 and 500?ppm. The nanoparticle and the ethanox are dispersed by the ultrasonication process. The addition of nanofluid reduces the particulate emission like nitrogen oxide (NO_x) at 100% load. The efficiency is better and emission is reduced owing to the influence of explosion of water molecules present in the biodiesel. We found ethanox to be a superlative nanofluid to reduce the emission of toxic gas at appreciable levels. We have witnessed a 20% reduction in emission of NO_x and 10% reduction of other particulate emission. In addition, the exit geometry of exhaust is modified from a circular shape to an elliptical one and the consequence of the geometry is calculated.     

Effect of the addition of 1-pentanol on engine performance and emission characteristics of diesel and biodiesel fuelled single cylinder diesel engine

ABSTRACT

Bioalcohols have recently become one of the promising alternate fuels. Lower alcohols exhibit some problems like phase separation, stability issues, storage problems, corrosion etc. Hence, the addition of higher alcohols is regarded least-problematic and the concept of using higher alcohols as fuel blends is relatively new. In this article, the effects of the addition of higher alcohol (1-pentanol) on engine performance and emission characteristics are discussed. Two reference fuels (diesel and biodiesel derived from waste cooking oil) and two test fuels (blends of 20% of 1-pentanol and 80% of either diesel or biodiesel) are tested in a single cylinder compression ignition diesel engine for six load conditions (0, 4, 8, 12, 16, and 20?kg) at a constant speed of 1200?rpm. The engine performance and emission characteristics are determined and discussed.     

Performance and emission characteristics of diesel engine operated on plastic pyrolysis oil with exhaust gas recirculation

The objective of this research was to study the performance and emission characteristics of using waste plastic pyrolysis oil in diesel engine without any engine modification. The engine used in this study is a four-stroke single-cylinder naturally aspirated diesel engine (compression ignition). In the present work, the engine fuelled with blends of diesel fuel (DF) with plastic oil in the ratio of 90:10 (blend10%), 80:20 (blend20%), 70:30 (blend30%), and 50:50 (blend50%) are experimentally measured the efficiencies and emissions, analysed the performance, and compared results with that of DF.     

Performance and emissions analysis of a diesel engine directly fuelled with waste cooking oil biodiesel

This research focuses on a comparative study of the physical and chemical properties of waste cooking oil (WCO) biodiesel with China stage IV diesel fuel. The estimate method of excess air ratio and the heating value ratio of an engine's cylinder mixture are proposed based on the differences of properties of two fuels. The bench tests of engine performance are carried out with an engine fuelled with two fuels separately. The estimated excess air ratio and the heating value ratio of an engine's cylinder mixture through the method are approximate to the experiment results. This comparison demonstrates that the estimate method can be applied to the performance analysis of an engine. Compared with China stage IV diesel, when a diesel engine is fuelled with WCO biodiesel, the torque and power decline from 1.9% to 13.8%; the brake-speci?c fuel consumption rises from 3.7% to 15.6%; CO, HC and PM emissions decrease significantly and NO_X emissions increase slightly.     

Performance and emission characteristics of diesel engine operated on tyre pyrolysis oil with exhaust gas recirculation

The objective of this research was to study the performance and emission characteristics of using waste automobile tyre pyrolysis oil (TPO) in a diesel engine without any engine modification. The engine used in this study is a single cylinder naturally aspirated four-stroke diesel engine (compression–ignition). In the present work, the performance and emission characteristics of the engine fuelled with blends of diesel fuel (DF) with automobile tyre oil in the ratio of diesel to waste automobile tyre oil of 90:10 (blend 10%), 80:20 (blend 20%), 70:30 (blend 30%), and 50:50 (blend 50%) are experimentally measured and analysed and compared with that of DF.     

Experimental investigation of performance and emissions characteristics on single-cylinder direct-injection diesel engine with PSZ coating using radish biodiesel

ABSTRACT

It has been determined that world oil production is likely to level off very shortly and that alternative fuels will have to meet the demands of an increasing energy crisis. The crude oil price is continuing to increase; at the same time the need of energy is also increasing rapidly. So there is an urgent need to switch to some other fuels which could replace petrol and diesel in order to produce energy. An eco-friendly alternative is required to fulfil the growing demand. This project highlights our work on alternate fuels and the importance of choosing radish seed as one such alternative. The aim of this study is the experimental investigation of performance and emissions on a single-cylinder direct-injection diesel engine with a coating. Diesel, B25, B50, B75 and B100 are used as fuels. The engine cylinder head, valves and piston crown are coated with 100 micron of nickel-chrome-aluminium bond coat and 450 micron of partially stabilised zirconia by the atmospheric plasma spray method [Ravikumar and Senthilkumar (2013). “Reduction of NOx Emission on NiCrAl-Titanium Oxide Coated Direct Injection Diesel Engine Fuelled with Radish (Raphanus sativus) Biodiesel.” Journal of Renewable and Sustainable Energy 5 (6): 063121]. Further, by using radish biodiesel and its blends, the emission and performance characteristics are checked and a suitable blend is selected.     

Study on the outcome of a cetane improver on the emission characteristics of a diesel engine

ABSTRACT

Dimethyl carbonate (DMC), a cetane improver, is used as a fuel additive to investigate the exhaust emission in diesel engine. Neem oil biodiesel (B100), neem oil biodiesel + dimethyl carbonate (B100+DMC) and diesel were used as test fuels. DMC is added 0.5% by volume to biodiesel. This research work was executed in a four-stroke, single-cylinder diesel engine. Owing to the percentage of DMC in biodiesel, carbon monoxide (CO) and hydrocarbon (HC) emissions were dropped corresponding to diesel. A considerable amount of nitrogen oxide (NO_x) is decreased when diesel is used, and by the addition of B100+DMC, NO_x were slightly reduced compared to B100.     

Experimental analysis of the effects of cerium oxide nanoparticles on a single-cylinder diesel engine using biofuel blended with diesel as fuel

Energy demand is the hot topic of all developing and developed countries. Energy demand has been increasing day by day at a high rate. So, it is necessary to find an alternative solution that is eco-friendly. Biodiesel can be the alternative solution for this problem. The main purpose of this paper is to test the engine performance and emission parameters of a diesel engine using pure cinnamon oil blended with diesel and using cerium oxide as a catalyst. The parameters measured are brake power, brake thermal efficiency, specific fuel conception, CO₂, CO, NO_x and HC.     

Experimental investigation on the performance and emission characteristics of CI engine using waste cotton seed biodiesel with ZNO as a fuel additive

ABSTRACT

The energy crisis created by depletion of fossil fuels and the toxic emissions from the fossil fuel demands for eco-friendly potential alternative sources of energy. Even though unclean, biodiesel is found to be a potential alternative for the fossil fuels. In the present work, the emission characteristics and performance of biodiesel blend with and without ZNO additive was studied. There are four biodiesel blends studied in the first part of the research and found that the B25 combination gives a better result compared to others; therefore, this blend is tested with three proportion of ZNO additive in the second part of the research. The addition of 125?PPM of ZNO to the selected B25 blends gives a better performance, the efficiency improvement is found to be 4.2% and the emission of NO_x is by 10.3% under full load condition.     

Investigation on the effect of thermal barrier coating at different dosing levels of cerium oxide nanoparticle fuel on diesel in a CI engine

ABSTRACT

In the recent times, the limitations on the exhaust emissions of the internal combustion engines are becoming increasingly rigorous due to environmental safety. Carbon monoxide, oxides of nitrogen, particulates and hydrocarbon are the prime noxious waste emitted by diesel engines. This experimental study involves the analysis of engine performance and emission characteristics of a single cylinder diesel engine with yttria- and ceria-stabilised zirconia coating on a cylinder liner and piston head. Varied dosing levels were added to diesel in both uncoated and coated engines. The experiment resulted in noticeable changes in the selected thermal barrier coating and dosing of cerium oxide additive nanoparticle in diesel. A surge of 2.1% in the brake thermal efficiency and downturn of 3% brake-specific fuel consumption when compared to standard diesel mode in the uncoated engine was discerned. Emission level of nitrogen oxide, carbon monoxide and hydrocarbon also underwent a considerable decline.